My invention relates to the production of pulp from fibrous ligno-cellulose materials, such as wood chips and other fibrous vegetable materials and more particularly to pulping processes which are generally termed "mechanical processes" in which the ligno-cellulose material is fiberized between the grinding discs of a refiner.
The refiner discs may either be of the counter-rotating kind or one of the discs may rotate while the other one is stationary.
In the latter instance the raw material is fed through the center of the stationary disc into the space between the discs and by the action of elements affixed to the rotary grinding disc the material is accelerated and by centrifugal forces finally conducted in between the grinding elements of the grinding zone.
The pulp produced is mainly intended for use in the manufacture of newsprint, cardboard, tissue paper and similar products.
As raw material, fibrous ligno-cellulose materials from wood or other plants, e.g. bagasse may be used. The method used can be classified as a mechanical process and can be carried out under normal atmospheric conditions or in a steam atmosphere at temperatures above 100.degree. C., generally at a temperature between 110.degree. C. up to 140.degree. C. or under special conditions in the temperature range between 150.degree.-170.degree. C. When the mechanical process is carried out at a temperature above 100.degree. C. it is generally classified as "thermomechanical".